Overdrive slipping?

Topic: Overdrive slipping? (Read 4609 times) previous topic - next topic

Overdrive slipping?

Reply #15 – April 24, 2012, 09:32:40 AM

Old thread revival.

My aod drives fine, but ive noticed if I get on it hard and it downshifts, It seems to slip some as accelerating.

Im thinking about getting a Silverfox valvebody anyway, would that hasten the aod's demise?

Overdrive slipping?

Reply #16 – April 24, 2012, 09:40:18 AM

Is it slipping when loading up in 4th (od)? Ie, you let it shift into 4th and then give it some more gas without it wanting to kick down? If so, thats what my SC did when the OD band went out.

If it flares when kicking down into 3rd (4th gear, give lots of gas, Lower RPM-REALLY HIGH RPM-High RPM) then most likely it is somewhere else. Might be the 3-4 acspoogeulator but I would have to go study the AOD some more. Folks at Click-Click racing might know.

-DZ

Overdrive slipping?

Reply #17 – April 24, 2012, 04:06:17 PM

It happend going fairly slow (like 30 mph) and stomping on it, downshifts good and takes off, begins to slip in upper rpms. I let off and it upshifts, and I think "WTF" just happened and get pissed.

Overdrive slipping?

Reply #18 – April 24, 2012, 04:47:24 PM

I'm going to preface this with saying: The following are educated guesses from a guy on the internet who has fooled around with a couple AODs. Please refer to a certified mechanic if don't feel very confident mucking with your only mode of transpiration.

So you are cursing along in 30 (probably in 3rd) and you stomp on it. There should be a firm kick to 2nd and then hold 2nd till you hit X RPM (it's been a while since I had an AOD). At which point it will attempt to shift into 3rd. <>

If it's flaring on the 2-3 shift, the clutch is not applying fast enough allowing too much slip in the shift. Some likely culprits are the 2-3 shift acspoogeulator or 2-3 shift valve or one of your clutches have started to give up (probably from the former going out, can't remember if it's the front, intermediate, or direct clutch which is responsible for the 2-3 shift).

If you are confident with taking parts of your trans apart, I would try inspecting the 2-3 acspoogeulator and 2-3 shift valve. You need to pull the VB to get to the acspoogeulator so you may as well check both.

Not as scary as you might think but will cost you ~$30 in trans fluid and another ~$30 in a gasket set. You will need to be very clean and clean both the VB, separator plate, and trans case. You will need a small torque wrench as well. Can be done without removing the trans. I replaced the 2-3 acspoogeulator seals when I did the OD band replacement because I was already in there.

Check out this recommendation.
http://www.justanswer.com/ford/20wae-1992-ford-f150-4wd-the-transmission-shifts-neutral-second-gear.html

These clutches are buried in the trans assembly and would basically call for a complete tear down.

Overdrive slipping?

Reply #19 – April 26, 2012, 11:02:45 PM

Quote from: 88CougarGT;387723

So you are cursing along in 30 (probably in 3rd) and you stomp on it. There should be a firm kick to 2nd and then hold 2nd till you hit X RPM (it's been a while since I had an AOD). At which point it will attempt to shift into 3rd. <>

Yeah if I I was stuck at 30mph I would probably be cursing as well.

As far as the above statement, I don't think it would be in 3rd at 30 mph unless you've got a high geared rear. But I can say that my AOD will stay in 2nd gear if I'm WOT until about 70 mph, which is somewhere around 4500 rpm I believe. But this could also vary a bit based on the TB cable adjustment. The upshift to 3rd should definitely feel smooth but not drug out. Pretty much instant.

Overdrive slipping?

Reply #20 – April 26, 2012, 11:55:32 PM

It COULD in fact be in 3rd when cruising even with a numerically low rear end gear depending upon how you've set the TV valve. Where I have mine right now, the car will not shift into 3rd even at the absolute lightest throttle until 35 MPH. This is with a 27 inch tall tire and 3.45's. Depending on if I move the block back more or forward more on the rod, I can adjust this a good amount. The car will grab 1st gear up to 32-33 MPH depending upon temperature conditions if I mat the pedal down.

Quote

But I can say that my AOD will stay in 2nd gear if I'm WOT until about 70 mph, which is somewhere around 4500 rpm I believe.

It's more due to inherent converter slippage in 1st and 2nd. Case in point. I get about 80 MPH in second gear and I'm turning 6 grand on the motor at that point. If there were zero converter slippage I should get about 10 MPH MORE. The car would accelerate a hell of a lot slower though. Tradeoffs suck.

Overdrive slipping?

Reply #21 – April 27, 2012, 11:19:46 AM

As far as adjusting the cable goes. I tried all sorts of combinations. I found that adjusted too tight results in the more aggressive quick shifts I liked, but sometimes it would "hang" waiting on the downshift. Basically, it would stick it out in 3rd too long when coming up to a light. I finally settled on somewhere in the middle giving me firm shifts but coasting to stops normally.

I had 3.55s and 26" tall tires and an SC engine pushing 300ish ftlbs torque. If I was on anything but the freeway I drove around in 3rd (D). Otherwise with the 355s it wanted to kick into OD at 40ish. Resulting in a alot of shifting in-out-in-out. I would really recommend city driving in 3rd for any AOD owner. That OD band sucks (1.5" wide for most of us) and just heats up the oil with all the shifting.

Man I miss that car.

Overdrive slipping?

Reply #22 – April 27, 2012, 04:16:06 PM

Quote from: 88CougarGT;388132

That OD band sucks (1.5" wide for most of us) and just heats up the oil with all the shifting.

The most common solution is to replace it with 4R70W parts. Its a much better band. 2" IIRC

Overdrive slipping?

Reply #23 – May 18, 2012, 03:25:40 PM

Update. So I've been driving around in (D) for about a year now and finally tried (OD) out again. It seems to be doing fine now. I wonder if I had gotten some trash in the fluid or something that worked it's way out.

Overdrive slipping?

Reply #24 – May 18, 2012, 03:58:47 PM

Magic Healing Car.

I had a 92 topaz that was a magic healing car. It would make all sorts of horrible noises that would slowly go away. I thought everything was fine and dandy. Then one day the transmission just disappeared.